What do roots do? They provide the tree with water and minerals from the soil. They serve to anchor the tree so that the first windstorm doesn't blow it over! And just as important, they help to hold the soil around the tree.
Trees are used extensively to reduce the risk of landslides and to prevent rivers from washing away soil.
Vegetation planted along rivers beautifies the banks and plays an important role in the protection of river ecosystems. Willows and alders are just two of the species that thrive under the difficult conditions along river banks. They like being close to the water and stand up well to the action of ice and flooding. Their extensive root networks are very efficient at retaining the soil.
Riparian land (located along water courses or bodies) is a very rich and important environment. It constitutes the transition zone between the water and solid ground. It also provides refuge, food, and a gathering place for a great number of animals. Its vegetation reduces erosion by slowing the flow of water and by stopping particles of soil carried by the water (sedimentation).